Process of obtaining pure metallic copper from a solution of a salt of copper.



UNITED STATESPf TENT oFFIcE,

LUCIEN JUMAU, OF PARIS, FRANCE PROCESS OF OBTAINING PUIRJE METALLIC COPPER FROM 'A SOL UTION OF A SALT OF COPPER.

Specif cation of Letters Patent.

Patented Aug. 10, 1909.

Original application filed January 19, 1907, Serial No. 353,064. Dividedvan d, this application filed April 21, 1908,

a sesame. 428,412.

To all whom it may concern:

Be it known that I, LUCIEN JUMAU, a citizen of France, resldlng at Paris, in the said Republic, have invented new and useful Improvements in Processes for Obtaining Pure Metallic Copper from a Solution of a Salt of Copper, for which I have obtained a patent of addition in France, No. 6.825, bearing date October 27, 1906, of

which the following is a specification. I

The presentapplication is a division'of an application, Serial No. 353,064, "filed January 19, 1907, for Letters Patent of the United States.

My invention relates -to an improved proc css for obtaining pure metallic copper from a solution of a salt of copper, and it con presenceof sulfurous acid; in this process,

the copperis precipitated from the solution in the form of pure metallic copper, and the sulfurous acid is oxidized to sulfuric acid, according to the equation:

When a solution containing salts of copper is thus heated under pressure, in the presence of sul-flirous acid, the percentage of copper precipitated in a pure metallic form increases as the temperature is raised. As an example, in a copper sulfate solution having originally a concentration of twentytire grains-per liter, the percentage of cop &

per precipitated in a pure metallic form will be increased by raising the temperature substantially as follows Temperatures. 00291961" prccip i25 fad.

140 C 47% 155 C (;2% 167 (3 65* 190 C 79%.

Therefore, the employment of a temperature as high as possible is essenhal to the operation of my rocess and my invention has just for its 0 ject a process by which the utilization of such high temperatures will not be impracticable by a corresponding increase in the pressure en endered thereby. In fact, when treating so utions saturated with sulfurous acid, the pressure increases rapidly with the temperature, notonly owing to the pressure of aqueous vapor corresponding with the concentration and the temperature, but to the pressure engendered by the sulfurous acid.

' In order to permit the employment of ,high temperature without attaining such a high pressure, the latter: is diminished,-according to my improved process, either by introducing into the solution only that quan tity of sulfurous acid which correspondswith the theoretical equation above mentioned, without attaining saturation, and then heating the whole gradually; or by first heating the solution, Without sulfurous acid, and then introducing the latter as gas under pressure in such a manner as to add gradually only the theoretical quantity, the f, said addition being made in proportion as the sulfurous acid becomes sulfuric acid.

I have described my preferred process, but, obviously, changes could be made within the spiritand scope of my invention.

'Having thus described my invention, what I claim as new and desire to secure by Letters-Patent is: I

1. The process of precipitating copper from a copper sulfate solution, which consists in subjecting the said solution to a high temperature, adding thereto sulfurous acid and n'laintaining a safe pressure by so roportioning the amount of the added acid as to satisfy the chemical equivalents without saturation.

The process of reducing copper from a copper sulfate solution which consists in subjecting the saidjsolution to the action of heat and pressure,in the presence of s'ulfurous' acid, and gradually increasing the temperature of thetiningled ingredients.

In testimony wltereof, I have signed my name to this specification in the presence of two subscribing witnesses.

LUCIEN 'J UM AU.

Witnesses JULns FAroLLn'r, l ltnninn PICHON. 

